Control method of thermostatic system

Abstract

A control method of a thermostatic system for a hot water heater is provided where when the water temperature in the hot water heater is too large, a first electromagnetic valve is controlled to be open and a second electromagnetic valve is controlled to be closed. Gas will be transferred via the first gas room to the second gas room. The control of the electromagnetic valves causes a decrease in gas outflow to the hot water heater. When the water temperature in the hot water heater is too small, the first electromagnetic valve is controlled to be closed and the second electromagnetic valve is controlled to be open. The further control of the electromagnet valves causes an increase in the open degree of a gas outlet valve, hence increasing gas outflow.

I claim:  
     
       1. A control method of a thermostatic system for a hot water heater, comprising the steps of: 
       a. providing a thermostatic system having a gas inlet for input of gas, a first gas outlet for supplying gas to a hot water heater, a water inlet for receiving for input of cold water, and a water outlet for fluid communication with the hot water heater, said thermostatic system having (1) a water pan coupled in fluid communication with said water inlet and said water outlet, said water pan having a thimble coupled to a first gas-valve for passing gas from said gas inlet to a chamber responsive to cold water being input to said water pan from said water inlet, (2) a second gas valve disposed between said chamber and said gas outlet, said second gas valve being adapted to provide proportional gas flow from said chamber to said gas outlet, (3) a switch seat coupled in fluid communication with said chamber for receiving gas therefrom, said switch seat having a first gas room and a second gas room partitioned by a diaphragm, said diaphragm being coupled to said second gas valve by a connecting link, said first gas room being in fluid communication with said chamber (4) a first electro magnetic valve having a inlet coupled in fluid communication with said first gas room and an outlet coupled in fluid communication with said second gas room, and (5) a second electromagnetic valve having a inlet coupled in fluid communication with said second gas room and an outlet thereof coupled in fluid communication with a second gas outlet;  
       b. controlling said first electromagnetic valve to be open and said second electromagnetic valve to be closed to thereby transfer gas from said first gas room to said second gas room and equalize pressure on opposing sides of said diaphragm to close said second gas valve;  
       c. controlling said first electromagnetic valve to be closed and said second electromagnetic valve to be open to transfer gas from said second gas room to said second gas outlet, responsive to said transfer of gas from said second gas room said diaphragm is displaced toward said second room to proportionally open said second gas valve and thereby transfer gas to said first gas outlet; and,  
       d. controlling said first and second electromagnetic valves to close responsive to water in the hot water heater is within a predetermined temperature range, repeating step c responsive to the water in the hot water heater being lower than said predetermined temperature range, repeating step b responsive to the water in the hot water heater being higher than said predetermined temperature range.